bug#56323: 29.0.50; [v2] Add new customisable phonetic Tamil input method

[Eli Zaretskii]

> From: समीर सिंह Sameer Singh <lumarzeli30@gmail.com>
> Date: Sat, 2 Jul 2022 16:35:51 +0530
> Cc: Eli Zaretskii <eliz@gnu.org>, 56323@debbugs.gnu.org
> 
> There is indeed a principle behind the ordering of letters in Indian 
> languages taken from Sanskrit, and AFAICT
> Tamil also follows it.
> 
> க் ங்
> ச் ஞ்
> ட் ண்
> த் ந்
> ப் ம்
> 
> If we look at it rowwise, the first row is the velar consonants, then the 
> palatal then retroflex then dental then
> labial. If you notice here, we are gradually moving from the back of the 
> mouth to the front!
> 
> If we look at it columnwise the first column consists of unvoiced/voiced 
> consonants and the second column
> consists of nasals.
> 
> Then come the semivowels
> ய் ர் ல் வ் ழ் ள்
> 
> After that 
> ற் ன்

Thanks.  If there's no existing property of characters that we could
use to produce this order, I guess we will need an alist of characters
and their ordinal numbers, and use that.  Or, if the codepoints of
these characters are contiguous, we could have just the ordinal
numbers in the order of the codepoints, and use that in the function
passed as the PREDICATE argument to 'sort'.